crossing over at about 45hz, I have Omnimic so I guess I can use that. Place the mic in the listing position and set each woofer separately (with mains) , then both subs?
This is the procedure that works well for me with REW:
A good starting place for the sub controls is:
PEQ - Off
Delay/Phase - 0
Crossover - something close to the -6 point of the main speaker. It's important to note that the numbers on the dial do not correspond to an actual frequency, especially with the open baffle configuration. Rythmik uses the same silk screen for their sealed/ported and open baffle configurations. What they do is take a sealed/ported amp and add an open baffle shelving circuit for OB use. It would be too expensive to have different silk screens for the different models. This means you have to rely on that the REW graph shows to get the setting right and ignore the printed numbers.
Level - 12 o'clock
Low Pass - EXT/12
Rumble Filter - Off
Extension filter FREQ - 14 Damping - Low
When I'm dialing in subs I place the mic at the main listening position. After getting REW set-up, start taking measurements of one channel only (either L or R):
Turn the sub off and run a sweep of the main speaker
Notice the average SPL and where the main speaker is -6dB down from that average. Run a few sweeps and average the results if you like.
Turn the main speaker off and the sub on
Run a sweep and see what the output level of the sub is like. You are going to adjust the sub's volume until the average output is where you want it compared to the average output of the main speaker. I prefer the subs average volume to be 2 or 3 dB higher than the average of the main speaker. Your preference might be different.
Adjust the sub's volume control and run another sweep. Keep doing this until the sub's average SPL level is where you want it.
Now adjust the sub's crossover control to get the sub's -6 point the same as the main speaker. Keep running sweeps and adjusting the crossover control until the sub and main speaker are -6 at the same frequency.
Now turn the main speaker back on and run a sweep with both the main and sub playing. They should sum at the crossover point giving a smooth frequency response. If they don't there is likely a phase issue between the main and sub. If the phase responses are far enough off, instead of summing they can cancel making the -6dB point dip even lower.
If they don't sum to a smooth response, adjust the phase control and run another sweep. Compare this with the previous sweep to see if the phase issue is getting better or worse.
Continue adjusting the phase control and running sweeps until the main and sub sum to a smooth response.
Now if there are any big peaks or dips in the bass response it is time to turn on the PEQ function. Usually you want to reduce a peak. Boosting a dip with the PEQ is difficult.
Once this channel is dialed in, repeat the process with the other channel.
Once that one is also dialed in, run a sweep with both channels on. If something is off now, you have to determine whether you need to redo the dial in process, move the speaker(s), or add room treatment. It's not unusual to find the center image is no longer centered. If that happens, adjust toe-in until the image is re-centered then run another sweep with both speakers playing.
It's not unusual that changing one setting has an effect on something else. You just have to keep moving back and forth until you get a result you like.
